In the foundry, during the process of forming ductile iron, casting involves a reaction with molten iron and magnesium. The magnesium reaction converts some of the carbon in the iron from thin wafers to spherical nodules. (Nodularization) These nodules give ductile iron improved strength, so it is critical that this reaction occurs. Ductile iron is also known as spheroidal graphite and nodular iron. It is desirable to promote precipitation of graphite within the iron in the form of spheroids rather than interconnected flakes. Magnesium is a rare earth metal and is very desirable for the formation of acceptable nodularity. Magnesium is a very reactive metal with low vapor pressure which can result in a considerable loss of magnesium during treatment. Introduction and control of magnesium is an essential and most important step in the production of ductile iron. In practice, sufficient amounts of magnesium are often introduced to retain a certain level of residual magnesium to ensure proper nodularization. However, excessive amounts of added magnesium may cause undesirable porosity and carbides. Too little magnesium will result insufficient nodularization. Thus, detecting nodularization during controlled introduction of magnesium during the molten process is extremely beneficial.
In a high production foundry, there is an essential need for a quick control detection/monitoring tool to ensure the sufficient quality (sufficient nodularity) of the molten metal before it is poured. This will be a well understood benefit to those of ordinary skill in the art. Because ductile iron is often used in safety critical structural components of a vehicle, ensuring proper nodulation is essential. For example, ductile iron is often used to form differential cases, carriers, end yokes, flanges, slip yokes and other structural components such as steering knuckles. Failure of steering knuckles will cause an operator to lose control of the vehicle. This has serious safety implications. Thus ensuring proper nodulation during production is essential to increasing the quality of any product. The present invention poses a simple and quick solution to ensure proper nodulation during the production process before the molten metal is poured.